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SURGICAL TECHNOLOGY INTERNATIONAL XIX
Use of Transparent Plastic Tubular
Retractor in Surgery for Deep Brain
Lesions: A Case Series
SEBASTIAN R. HERRERA, M.D.
NEUROSURGERY RESIDENT
PELAGIA KOULOUMBERIS, M.D.
NEUROSURGERY RESIDENT
JOHN H. SHIN, M.D.
NEUROSURGERY RESIDENT
EDUARDO GOELLNER, M.D.
NEUROSURGERY FELLOW
MICHAEL CHAN, M.D.
NEUROSURGERY RESIDENT
KONSTANTIN V. SLAVIN, M.D.
ASSOCIATE PROFESSOR
DEPARTMENT OF NEUROSURGERY, UNIVERSITY OF ILLINOIS AT CHICAGO
CHICAGO, ILLINOIS
ABSTRACT
B
rain tissue retraction is frequently required to reach deep intra-axial lesions, and the quest for an ideal
retractor that would protect the underlying brain tissue continues. Despite the availability of multiple
retractors, the incidence of brain retraction injury remains high and has been reported to be 5% to 10%.
A recently developed transparent tubular retractor appears to provide several advantages in surgery for deep
intra-axial tumors and intracerebral hematomas. We used a new commercially available transparent tubular
retractor in 16 craniotomies. Fourteen of these patients were operated upon for deep tumors and cysts,
including two intraventricular tumors and two for deep intracerebral hemorrhages. In all patients, the tubular retractor was directed toward the lesion through a small corticotomy and guided by a navigation system.
Each lesion was completely removed through the retractor's lumen. In all cases, the tubular retractors provided excellent visualization of the underlying pathology and facilitated its surgical removal, dissection, and
hemostasis. The tubular nature of the retractor allowed the rotation and changing the angle of approach
without putting extra pressure on the brain tissue, which inevitably occurs when malleable or other ribbontype retractors are used. There were no hematomas on routine postoperative CT scans in this series. Trans-1-
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Use of Transparent Plastic Tubular Retractor in Surgery for Deep Brain Lesions: A Case Series
HERRERA/SHIN/CHAN/KOULOUMBERIS/GOELLNER/SLAVIN
parent tubular retractors provide a unique means of deep visualization and even force distribution at the
retracted brain tissue. Although these retractors were originally designed for the removal of deep subcortical tumors, they may be used to access and evacuate intracerebral hematomas. In our experience, the use of
tubular retractors allows one to achieve safe access to deep intracerebral lesions and decreases the rate of
retraction-related complications.
INTRODUCTION
The issue of brain retraction has
been repeatedly discussed in the neurosurgical literature. The damaging effect
of the pressure put on the brain tissue
during surgical exploration of various
intracranial pathological processes is
well known, with the incidence of
postoperative intracerebral hemorrhages reaching 10% or greater, and
therefore we and others routinely use
multiple avenues aimed at the minimization of such potentially harmful
retraction. 1 Among others, these
include the development of approaches
around the brain tissue, the release of
cerebrospinal fluid by decompressing
Figure 1. Schematic illustration of the tubular retractor assembly (left), the retractor itself (center), and
the introducer (right).
the cisterns or through a lumbar drain,
the administration of diuretic and
hyperosmotic agents, hyperventilation,
and so on.2,3 However, all these measures do not eliminate the need for
brain retraction, particularly if one has
to reach deep intra-axial lesions such as
neoplasms, vascular malformations,
and hematomas. For this purpose,
there are many commercially available
retraction systems but most of them
have their unique setbacks.
For example, the standard flat malleable and tapered retractors do not
confor m to the cur vature of the
retracted tissue and are known to cause
petechial hemorrhages along the
retractor edge, presumably due to a
sharp gradient of pressure between the
retracted and surrounding tissues. To
overcome this problem, several
authors recently recommended using
tubular retractor systems, some of
which are designed for frame-based
stereotactic applications (COMPASS;
Compass, Inc., Rochester, MN) and
some are adapted from extracranial
applications (METRx; Medtronic,
Minneapolis, MN). 4,5 Both of these
tubular retractors are metal and do not
allow visualization of the retracted tissue, creating another limitation for
their wider acceptance.
Here we present the technical
aspects of a novel transparent tubular
retractor that was specifically designed
for intracranial applications and is
commercially available worldwide.
TECHNICAL
TECHNICALDESCRIPTION
DESCRIPTION
Figure 2: Intraoperative photograph illustrating the simultaneous use of bipolar forceps and suction
through the tubular retractor during tumor or hematoma removal.
-2-
According to its labeling, the
ViewSite tubular brain retractor
(Vycor Medical, Bohemia, NY) is
specifically designed for intracranial
applications. It is available in a variety
of sizes representing different lengths
and diameters suitable for different
surgical procedures. It is made out of a
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SURGICAL TECHNOLOGY INTERNATIONAL XIX
transparent plastic material and is individually packed in a sterile wrap, intended for a single use only. Each retractor
assembly consists of two parts—the
retractor and the introducer (Fig. 1).
The retractor itself has a slightly
tapered cylindrical shape with a circular
or ovoid cross-section. Its outer edge is
slightly wider and has a black outline
over the clear plastic structure. The
outer part of the retractor is attached to
a flat plate (tab) that may be used for
attachment to any of the widely used
retraction arms or serve as a handle for
manual insertion and manipulation.
The introducer is also made of a
transparent plastic material. It snugly
fits into the retractor and sticks out a
few millimeters from the distal opening
of the retractor cylinder, tapering down
to a very narrow flat surface that serves
as a dissector when the retractor assembly is inserted into the brain. The distal
tip of the introducer has a very small
opening that allows the egress of cerebrospinal fluid or blood during the
insertion process, and may also accommodate the tip of a pointing instrument
when this retractor is used in association with an image-guidance system.
The assembly is inserted into the
brain through a small corticotomy
either at the brain surface or in the
depth of a cortical sulcus after the
coagulation of superficial cerebral vessels and the sharp penetration of the
pial membrane. The image-guidance
probe may be used to facilitate the
insertion of the retractor and confirm
the direction of retractor advancement. The tapered shape of the assembly allows a smooth dissection of the
brain tissue between the cerebral surface and the underlying deep lesion.
The surface of the dissection corridor
may be continuously monitored by
visual observation due to transparent
nature of the assembly.
Once the lesion is reached, the
introducer is removed and the opening
in the distal end of the retractor allows
one to obtain visualization of the surgical field without either absorption of
light by the black surface of some
retractors or reflection of light from
metal surfaces of others. The direction
of the retractor may then be adjusted
during the course of lesion resection
by changing the angulation of the
device. Once the resection is completed, the retractor is removed by gently
sliding out of the brain while checking
Figure 3. Intraoperative photograph illustrating the manual control of the retractor by an assistant.
the walls of the retraction corridor for
bleeding.
CLINICAL
MATERIAL
CLINICAL
MATERIAL
We started using transparent tubular retractors in May of 2007. Here we
present our impressions from the first
16 consecutive uses of this device in
intracranial surgical interventions. In
two patients, a craniotomy was performed for the evacuation of deep
intracerebral hematoma and one for
drainage of a deep cyst, whereas thirteen other patients had intra-axial neoplasms. Of these, six were metastatic
tumors, five were deep gliomas, and
two were gangliogliomas.
Figure 4: Intraoperative photograph illustrating the use of a tubular retractor in conjunction with a selfretaining retractor arm.
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HERRERA/SHIN/CHAN/KOULOUMBERIS/GOELLNER/SLAVIN
We used two models of the
ViewSite retractor, 17 mm wide × 5
cm long and 21 mm wide × 5 cm long
in eight cases each. The size of the
retractor was chosen during the
surgery based on the size of the underlying pathological process. Each of
these retractors has an ovoid cross-section with width/height ratios of 17
mm × 11 mm and 21 mm × 15 mm,
respectively. Both of these sizes allow
the free manipulation of bipolar forceps, tumor forceps, and one or two
suction tips by a surgeon and assistant
working simultaneously (Fig. 2). The
length of the retractor channel (5 cm)
allows the reach of deep lesions when
the retractor is inserted completely
with its outer surface touching the cortex. In cases of more superficial
lesions, the retractor may be inserted
partially and held in place by an assistant (Fig. 3) or by a flexible arm of the
retractor (Fig. 4).
Intraoperative computer-assisted
stereotactic image-guided navigation
was used for the precise localization of
the deep intracerebral lesion in all
cases. In 10 cases, microsurgical dissection of the tumor tissue was perfor med with the assistance of an
operative microscope; in three other
tumors, the cyst and both hematomas,
loupe magnification was used.
In all cases, the lesions were
removed without complications. Nine
of the thirteen tumors were removed
totally and four subtotally. In one of
the cases, a ventricular catheter was
inserted into the ventricular cavity
through the retractor prior to its
removal. This catheter was subsequently connected to a ventriculoperitoneal shunt.
Postoperative computed tomography (CT) scans are routinely obtained
in all our patients that undergo craniotomy. The hematoma evacuation and
tumor resection were thereby confirmed in each case. There were no
instances of postoperative hematoma in
any of the cases reported here. Furthermore, tumor resection was confir med by postoperative magnetic
resonance imaging (MRI) in all cases
except one, who could not have MRI
due to implanted cardiac pacemaker.
DISCUSSION
DISCUSSION
New developments in brain retraction
technology are dictated by the need to
reduce risks and complications in elective
brain surgery. Much has been written
about the detrimental effects of excessive
cerebral retraction but to date the ideal
system that would make such retraction
absolutely safe still does not exist.2,3
Recently, an attractive idea was introduced to replace standard flat or curved
“blade” retractors with the tubular or
cylindrical models. The pioneering work
of Kelly and colleagues resulted in the
development of cylindrical retractors
that would be attached to a stereotactic
apparatus to facilitate volumetric resection of intra-axial tumors.5 A similar
device was later introduced by Otsuki et
al., and then by Ross and by Barlas for
use with a Leksell frame.6–8 Recently,
Greenfield et al. suggested using cylindrical retractors designed for minimally
invasive spine interventions for intracranial applications.4 Although revolutionary in thinking, neither of these two
developments created an ideal retraction
system, partially because the bulk of the
retractor is its metal or hard plastic texture and the lack of transparency of the
retractor walls resulted in limited acceptance of these devices by the neurosurgical community.
At the same time, another pioneering
innovation was aimed at developing a
nonmetal transparent retraction device.
Ogura et al. suggested using a transparent polyester film rolled into a cylinder
to retract the brain tissue en route to the
intracranial lesion.9 The limitations of
this approach include difficulty in inserting the film-based retractor into the
brain and the need for additional retractors to aim and hold the film in place.
The tubular retractor described in
this chapter combines the benefits of
these two principles. It has enough sturdiness to be advanced to the target, with
or without an image-guidance approach,
and at the same time is less traumatic and
completely transparent. We used two
sizes of the retractor that were available
at that time. Currently, the product line
includes 12 sizes of ViewSite device with
four transverse (larger) diameters (12
-4-
mm, 17 mm, 21 mm, and 28 mm) and
three lengths (3 cm, 5 cm, and 7 cm).
This choice of retractors adds more versatility and would significantly increase
their applicability in a variety of neurosurgical interventions.
CONCLUSIONS
CONCLUSIONS
Transparent tubular retractors provide a unique means of deep visualization
and even force distribution of the
retracted brain tissue. Although these
retractors were originally designed for
the removal of deep subcortical tumors,
they may be used to access and evacuate
intracerebral hematomas. In our experience, the use of tubular retractors allows
one to achieve safe access to deep intracerebral lesions and decrease the rate of
retraction-related complications. STI
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